mckibbin



L-B. McKlBBlN.

PROCESS FOR CONTROLLING THE TEMPERATURE OF ROLLING MILLS.

APPLICATION FILED MAY I6, 1919.

1- Patented Mar. 1, 1921 v 2 SHEETS-SHEET I.

I. B. McKIBBIN. PROCESS FOII CONTROL LING THE TEMPERATURE OF ROLLING MILLS.

I APPLICATION FILED MAY I6, 1919.

1,370,331. Patented Mar.1,1921.

2 SHEETS-SHEET 2.

Wines-sens: F2414" B73307:

UNITED STATES PATENT OFFICE.

, TOT-IN B. MCKIBBIN, OF GRAFTON, PENNSYLVANIA, ASSIG-NOR OF ONE-FOURTH T0 MARGARET IRENE SUGDEN AND DNE-FOURTH TO ISABELLA EDMONDS SUGDEN, BOTH OF PITTSBURGH, PENNSYLVANIA.

PROCESS FORCONTROLIPING TEMPERATURE. OF ROLLING-MILLS.

T 0 all whom it may concern:

Be it known that I, J OHN process for controlling thetemperature of:

rolling mill rolls. It has for its object to heat and maintain the rolls of a mill, preferably a two-high mill, at a desired normal temperature approximating the heat of the rolls in action, for the purpose of overcoming undesiredvariations n the contour or character of the rollsdue to their change from dimensions at normal temperatures to the sheet or bar and the rolls are approxi mately equal'in temperature, when the rolling operation must ordinarily be temporarily discontinued sufiiciently long topermit cooling by radiation. a

' These incidents attendantfupon the manufacture of various rolled material, and particularly sheet metal, usually involve many undesirable conditions and drawbacks, resulting in variations in the diameter and V contour of the rolls with resulting variations in reduction and cross section of the blank, increased cost, waste power, broken rolls, and other related parts directly resulting from unequally ,or over-heated rolls. i

It is a generally accepted fact among L those skilled in the art of hot rolling sheet Specification of Letters Patent.

lvfoKIBBIN, a citizen of the United States, residing at Grafton, in the county of Allegheny and iinfrii of Fig. 2; and

The present invention has in view to provide a method for so controlling the ternperature of the vrolls and their contour and diameter as to firstbring the. rolls by application of heat tov a temperature approximatlngthat of the rollsas usually imparted to them by the metal being rolled, 'so'as to keep the diameter and contour at an unvarying condition during-the rolling operations. The invention also hasin view to apply and maintain the heat to the body of, the rolls only, exclusive of their necks, and to reduce the tendency to breakage caused'by too' rapid contraction through be ng exposed to cooler temperatures, to a minimum.

" The invention utilizes any suitable heat, as preheated or waste hot air or products of combustion from a furnace or other suitable source, so controlled and regulated as to deliver a constant volume thereof to and around the roll bodies within surrounding inclosing casings, so constructed as to permit of the entrance and exit of the blank. Also to so arrange the distribution of such heating element that it will be applied principally to the middle of each rollbody, z. 6., that part of the. rolls'where the greatest amount of heat ordinarily accumulates by radiation from the blank or sheet being rolled. I 7 j One preferred embodiment of the invention is illustrated in the accompanying drawing'in which; j

Figure 1 is a view'in sectional elevation showing a stand of rolls provided with my improvement;

F'gr2 is a cross sectional view indicated by the line H, II of Fig. 1;

Fig. 3 is a horizontal section on the line Fig. 4 is a sectional detail view similar to Fig. 2 showing a modified construction.

Referring thereto, the rolls 22 are mounted'by their journals or necks 3 in housings 4., having the usual bearing brasses, adjusting screws, etc. commonly employed in such structures, and capable of being. set to the desired distance apart for intended operation.

For the purpose of protecting the rolls from'the action of the atmospheric air as much as possible and for confining around them the heating air, I provide surrounding Patented Mar. 1, 1921. Application filed. May 16, 1919. Serial No. 297,555, 7 I

shields or hoods 55 for the upper and lower rolls 22 respectively, spaced away therefrom a sufiicient distance to provide for an ample intervening body of heating air of substantially uniform thickness and for the adjustment of the rolls in operation. Between the upper and lower hoods 55 and coincident with the normal pass of the metal, clearance openings 6 at the entrance and exit positions are provided,

being made as narrow and restricted as practicable to prevent undue escape of the contained air.

Heated air is conducted to the interior of the hoods from any suitable source as a preheating furnace 7 of any suitable construction, as indicated in Fig. 1. In the form shown, I have provided for the preheating of the pack of sheet metal and for a plurality of return passes therethrough before the same is delivered to the stand of rolls over the conveyer table 8, although it will be understood that the invention is in no way limited to such particular form of the heating furnace, and may be combined with any suitableor convenient source of waste or generated heat.

In the construction shown, the gases of combustion for circulation through the heating interior of the furnace 7 pass downwardly by port 9 and conduit 10 to the outlet stack. Hot air or vapor conduit 11 communicates with the heated gases in any suit able manner, as indicated, and is connected by conduit 12 with the interior of the hoods 5 by branch pipes or conduits 13-13, as indicated in Fig. 2. The main conduit 12 is provided with various accessories for controlling and introducing the flow, as a valve 14 and a rotary or other type of fan or blower 15. I also provide a mixing device for the admission of cold air, as by means of the adjustable inlet control 16 and, for the purpose of indicating the temperature of the air at all times, a pyrometer gage 17 is connected with the conduit 12, as indicated.

Each branch connection 13 is provided with an independent controlling valve 18 whereby the amount of heated air distributed to each roll may be accurately regulated. Ordinarily, the lower roll is somewhat more protected than the upper roll of a stand and the resulting variation in radiation is apt to affect the temperature of the rolls unequally so that such individual control of the heated air is desirable in order to affect each roll the same.

The delivery terminal of each branch 13 extends inwardly through the end wall of the hood 5 adjacent the end of the roll and substantially throughout the length of the roll body at the top and bottom, as indicated in Fig. 2. The lower and upper portions respectively of conduits 13 are provided with series of perforations 19, as indicated in Fig. 3, preferably arranged in the manner and of varying sizes, as shown, so as to supply the main volume of heating air to the middle portion of each roll.

In Fig. at I have shown a modified arrangement of the hot air supply mechanism in which the branch conduit 13 extends inwardly from the main conduit 12 at top and bottom, and is connected at the middle top and bottom portion of the hood 5, delivering directly into the middle interior thereof. When desired, the individual branch conduits may be provided, as indicated in Fig. 4, with individual mixers 16 for admission of cold air, a pyrometer 17 for indicating the temperature, and a controlling valve 14 for accurate adjustment of the supply. By such means, it will be readily seen that the conditions are brought under the accurate control of the operator at all times, so as to vary the degree and volume of the heated air coincidental with any variations in local conditions as to atmospheric temperature, temperature of the material being rolled, or other incidents.

The construction and operation of the apparatus will be readily understood from the foregoing description. It is desirable that the rolls shall be first brought up to a temperature approximating that which is ordinarily imparted to them by the sheets or other material being rolled, so that thereafter, the introduction to the rolls and the radiation by the rolls will not substantially affect the rolls themselves as to undesirable variations resulting in expansion or contraction, and accompanying undesirable variation in the pass.

Should, however, there be any additional heat imparted to the rolls by the passage of the sheet therethrough, the subsequent intermission will permit of sufficient reduction of the temperature by radiation. That is to say, before the next sheet passes through, any increase of temperature will be correspondingly reduced by the volume of lower air temperature which surrounds the rolls, so that the rolls will return to their former degree of heat, but not to a lower temperature.

For instance, with a two-high stand of rolls or say 26 inches in diameter with a roll speed of 80 R. P. M., a roll delivery P. M. of 520 feet, a roll temperature of 200 F., delivering one 25 foot sheet in 5 seconds, will assume a temperature of about 225 F. with a normal roll temperature of 200 F. and an interval between each pass of 50 seeonds, such time will be sufiicient for a reduction of such additional 25 degrees during each such intermission. The conditions, however, may be readily and very accurately controlled in the manner above indicated.

The advantages of the invention will be readily apparent to those skilled in the art, and it will be obvious that the invention may be applied to many and various constructions of rolling mills, and that it may be changed or varied in different features or details by the skilled mechanic, but that all such changes or variations are to be considered as within the scope of the following claims.

What I claim is:

1. The process of preliminarily heating the rolls of a rolling mill to approximately rolling temperature consisting in enveloping the rolls by a heating medium and maintaining the same during rolling.

2. The process of preliminarily heating the rolls of a rolling mill to approximately rolling temperature consisting in enveloping the rolls by a fluid heating medium of substantially uniform thickness and confining the same around the rolls 3. The proces of preliminarily heating the rolls of a rolling mill to approximately rolling temperature consisting in inclosing the rolls within a surrounding casing with a substantially uniform intervening space and conducting a fluid heating medium from any source of supply thereto.

4. The process of preliminarily heating the rolls of a rolling mill toapproximately rolling temperature consisting in inclosing the rolls Within a surrounding casing With a substantially uniform intervening space and conducting a fluid heating medium from any source thereto and. regulating the volume and temperature of such medium.

5. The process of preliminarily heating the rolls of a rolling mill to approximately rolling temperature consisting in inclosing the rolls Within a surrounding casing With a substantially uniform intervening space and conducting a fluid heating medium from any source thereto under pressure and regulating the volume and temperature of such medium.

In testimony whereof I hereunto aflix my signature.

JOHN B. MQKIBBIN. 

